SMOOTH OPERATOR: Don Draper (played by Jon Hamm) may be a bore with nothing nice to say, but he’s the glue that holds “Mad Men” together.

They’ve been gone for 17 long months — the drunk and orderly ad men and women of “Mad Men.” But the whole bunch showed up on my doorstep last Friday, all wrapped up in a bright, red package.

Christmas in March.

Of course, I invited all my girlfriends over to watch, and, of course, we sat rapt through the entire two-hour premiere episode. And, trust me, for this group to sit still and not refill for the whole time is a feat in and of itself!

As usual, it is visually stunning, and, as usual, it’s also chock-full of — what? — well, I’m not sure.

The reality is that “Mad Men” is like baseball. The more nothing that happens, the more riveting it somehow, irrationally becomes. Anticipation is a kind of excitement.

The show is still WASPs behaving badly, old-school edition.

You’ll never see these characters involved in the revoltingly uncivilized antics of say, “Real Housewives” or the waxed-brow incivility of the “Jersey Shore.”

“Mad Men” is all about being civilized — while doing all the fun things we now consider highly uncivilized: smoking, drinking, unprotected sex, getting drunk at lunch, eating red meat, driving your kids around without the benefit of the straitjackets we refer to as car seats and sneaking out of work in the afternoon for a rendezvous at the Waldorf.

It’s not the sneaking-around sex our new age despises. It’s, God forbid, missing a minute of work!

Again this season, it’s all Don Draper (Jon Hamm) all the time. Without Don, the show, the agency, none of it would matter.

But why?

In reality, Draper’s a bore who never has a kind word to say to anyone, is a bad father, dislikes most women, is hardly the guy you’d follow into battle and, frankly, I’ve yet to see him come up with an ad campaign that’s a winner. The clients never even like them.

Sure, the show is setting up some very interesting scenarios with the other characters like new mama Joan and more-rotten-than-ever Pete.

Then, there’s Don’s new wife, Megan, of the giant choppers, who is a French, spouting (and singing and burlesqueing) seductress.

Even uptight Lane will have a very skeevy break in his usual mores.

But no matter how bizarre, ambitious and ’60s-quirky the rest of the mad ad crew is, it’s Don Draper who holds the show, like the agency he fronts, together.

He’s a hunter who has no respect for his prey.

And make no mistake, we, the viewers, are as much his prey as those dopey women who fall for him and the clients who adore him.

Yes, he’s the best empty suit you’ll ever come across and somehow we can’t get enough — of what little there is to the guy.

I can’t help but think, though, if Draper was 40 in 1966, then he’s now 85 years old!

Wonder if this octogenarian is still knocking back the gin-soaked olives at lunch and knocking the ladies literally off their feet at night.